The invention relates to AAR Standard F and E type railroad car couplers, especially to the knuckles used in these couplers. More particularly, the invention relates to improvements in the lightweight knuckle which is described and claimed in United States patent application, Ser. No. 08/636,033 filed Apr. 22, 1996, which is made a part of this application. Such lightweight knuckles can be used to replace existing, heavier AAR Standard knuckles.
For example, lightweight knuckles can be used in an emergency to replace AAR Standard knuckles which become damaged during operation. AAR Standard knuckles weigh approximately 78 to 88 pounds and are presently carried in the locomotive section of a train to replace any knuckles which become damaged and inoperable during operation of the train. In some cases, it may be necessary for a single operator to carry such a knuckle the length of 25, 50 or even 100 railroad cars to reach a defective knuckle which needs replacement. Then the operator must manipulate the replacement knuckle into position on the coupler, after the damaged knuckle is removed, which is no simple task. In fact, it is a necessary and important job, but a back breaking one to say the least. The invention is designed to alleviate this problem by the provision of a substantially lighter weight knuckle which weighs only about 48-54 pounds, or substantially less than an AAR Standard knuckle. Most importantly, the integrity of an AAR Standard knuckle has not been compromised. That is, this new lightweight knuckle will function or operate the same as an AAR Standard knuckle in relation to the other components of the coupler and those of an opposing coupler during, for example, the coupling and uncoupling operations. The goal of this invention is to design a lightweight knuckle which will eventually replace the much heavier AAR Standard knuckles in use today.
Briefly stated, careful stress analysis tests have been performed on AAR Standard knuckles to determine what areas of these knuckles can be reduced, in size or weight, or even eliminated without adversely effecting the function or operability of the knuckle. The result is a lightweight knuckle which has a unique contour or shape with different coring, both of which features are designed to eliminate extraneous material inside and outside the knuckle to produce, from a practical standpoint, the lightest possible knuckle which has sufficient strength to withstand the draft or pull loads and the push or buff loads, both of which loads are imposed upon existing AAR Standard knuckles during operation.
This lightweight knuckle utilizes industry standard grade E steel alloy material for excellent strength, toughness, and wear properties, and is compatible with all conventional knuckle type railroad freight car couplers. Moreover, the other conventional components of this lightweight knuckle, such as locks, throwers, and AAR Standard mating knuckles, do not need modification, but are fully compatible with this lightweight knuckle. Also, all industry standards as to form, fit, and function of a standard knuckle, such as 10A contour angling, coupling and gathering angles, lock drop and support, and anti-creep functionality, are maintained and not compromised.